Patent GB-954014-A (GB)
Title: Master and slave arm manipulating apparatus
Inventor: GRAINGER IRVIN RICHARD
IPC: B25J3/00
Filed: 1960-01-15
Abstract: 954,014. Handling radio-active material. PYE Ltd. Jan. 13, 1961 [Jan. 15, 1960], No. 1585/60. Heading B4Q. In a master and slave manipulator in which the master and slave arms are pivoted to opposite ends of a through tube extending through the shield wall of a cell, the slave arm is enclosed in a flexible bag which extends around the through-tube and is attached at one end outside the cell, the other end of the bag being formed with two finger portions which are attached respectively to two portions of a manipulating tool or to tool receiving members carried by the slave arm and a releasable connection between the slave arm and said two portions of the manipulating tool or said tool receiving members. As shown, Figs. 1, 2, the flexible bag 5 has two fingers 7 provided with beads 7a engaging grooves 8 in a pair of jaws 4, these jaws being detachably connected by spring-urged plungers 9 to studs 11 movable by linkages 2. Quadrants 3 connected to the linkages are controlled by the master arm by wires or tapes extending through the through tube 16 and slave arm. The bag extends around the through tube 16 through the shield wall and is sealed at 6 outside the cell enclosed by the wall. In order to service the slave arm or renew the bag 5 the slave arm is raised from its normal position B to a horizontal position A to engage a support 13 on the cell wall. This support includes ramps 12 which disengage the plungers 9 from grooves 10 in the studs 11 whereby the slave arm and through tube 16 may be withdrawn through the wall, the jaws 4 and bag being retained by the support 13. If the bag is to be replaced, a tool with a new bag sealed thereto is connected to the slave arm and the latter inserted in the cell, the previous bag together with the jaws 4 being discarded on the cell floor. If it is desired to replace the slave arm into the same bag the support 13 permits the studs 11 to be relocated in the jaws 4 and the plungers 9 to be re-engaged with the grooves 10. In a modified slave arm, Figs. 3a, 3b, the jaws 22 are mounted on tool-receiving members 21 by key and slot arrangements 23, 24 locked by spring-loaded pins 27. Each member 21 has a recess receiving a spigot 20 carried by the end of a respective linkage 2 and is detachably connected to its linkage by a spindle cam 25 received in a recess 20a in the spigot. The fingers 7 of the flexible bag are sealed to the members 21. In order to change the jaws 22 they are inserted in a rack in the cell having pins which enter jaw holes 28 to depress the locking pins 27 and permit removal of the jaws by a subsequent sideways movement applied to the key and slot arrangements 23, 24. Further tools may now be selected from other racks provided in the cell and be secured to the slave arm by appropriate movements of the master arm. To remove the slave arm for servicing the jaws are first removed and the slave arm moved into a horizontal position to engage a support 13 as in Fig. 2. The master arm is manipulated so that levers 26 on the spindles 25 are rotated to align cam flats 25a with the spigots 20 whereby the slave arm may be withdrawn from the members 21. In a further modification (Fig. 4, not shown) the releasable connections between the linkages 2 and the members 21 include spring-urged release buttons, these buttons being within the fingers 7.